NEW YORK (CBSNewYork/AP) — The family of an unarmed National Guardsman killed by police during a Queens traffic stop is taking the first official step toward a lawsuit.

A lawyer for the family of Noel Polanco filed a notice of claim Wednesday against New York City and Detective Hassan Hamdy who fired the fatal shot after a grand jury last week voted not to indict him.

“The family of Noel Polanco believe justice has not been served with the decision of the Queens grand jury,” family attorney Sanford Rubenstein said in a statement.

Polanco was killed on Oct. 4 when he was shot by Hamdy on the Grand Central Parkway near LaGuardia Airport. Police said Polanco had been pulled over for driving erratically and for cutting off an unmarked Emergency Services Unit vehicle.

Authorities said the 22-year-old Polanco initially resisted police efforts to pull him over.

Hamdy’s lawyer says he fired after he saw Polanco reaching under his seat with both hands. He said his client “felt threatened and was left with no other alternative other than the actions that he took.”

But a passenger in Polanco’s car has disputed that account. No weapon was found.

On Saturday, Polanco’s mother, Cecilia Reyes, said she would keep fighting for justice.

“I’m angry and I’m hurt, they didn’t do the justice they needed to do for my son,” Reyes told a group of reporters.

An attorney for the National Action Network called the situation problematic.

“The fact that an officer can go into a grand jury and simply say, ‘I thought he had a gun’ and there’s no indictment, we think that that’s a problem,” said lawyer Michael Harding.

The city law department said it would review the papers when it received a formal copy.